When the solar industry gathered at the Solar Power International a year ago, the mood was buoyed by the extension of a 30 percent investment tax credit that Congress approved only a few weeks earlier.

Although Lehman Brothers had recently collapsed, some executives weren't so sure whether the financial market crisis would exert a significant impact on the solar business.

This week, the industry meets again at Solar Power, this time in Anaheim, and the mood may be cautiously optimistic for the upcoming year.

Money and policy will be key topics, given the industry's reliance on federal and state programs to help finance manufacturing and large-scale installations. The intersection of solar and real estate development, including affordable housing, also will be an interesting discussion.

And, of course, the conference menu includes talks about the latest developments in thin films, concentrating photovoltaics and solar thermal power.

Company executives and analysts are all begging (hoping) 2010 will be a better year than this. The optimism isn't fueled by blind faith. Although the federal government passed the stimulus package in February, it became apparent fairly quickly its benefits wouldn't be fully felt until 2010 (see Reality Check: How Much Impact Can the Feds Have on Solar").

Aside from the federal incentives, Solar Power participants will be mulling over state net metering and rebates, as well as policies outside of the country. Europe continues to be the biggest market, thanks mainly to feed-in tariffs that guarantee long-term pricing of solar electricity and mandates that utilities must buy what solar electricity is available for sale (up to a limit, in many cases).

Advocates have always insisted that solar energy is affordable for consumers. The reality is that each solar energy system is a big-ticket purchase, even after rebates.

Questions about how homeowners and buyers put a value on solar panels are bound to emerge if solar gains wider acceptance. There is a panel session on Thursday at Solar Power that would dive into this issue.

Next year is likely see the construction of the first large-scale solar thermal power plant in the United States in about two decades. BrightSource Energy believes it could secure all the necessary permits and financing to begin building the 440-megawatt Ivanpah Solar Electricity Generating System in California's Mojave Desert in early 2010 (see BrightSource Gets Big Brother in Bechtel).

BrightSource and other solar thermal power developers have inked high-profile, large projects with utilities in California, Arizona and Nevada. These developers need a success story to show they could construct these massive build-outs without many delays and deliver fairly cheap electricity.

These projects are facing strong environmental opposition because of their scale and locations (see BrightSource Energy Ditches Project in Eastern Mojave). The same is true for similar-sized projects using solar panels. Many of these projects developers will be discussing these policy, financing and public relations challenges at the conference.